NATIONAL TELEPHONE COMPANY
B620

BATTERY INTERCOMMUNICATION TELEPHONES

"REPLY-AND-CALL" SUB-STATION AUTOMATIC

TABLE SET

Pattern No. B620

Comprises the same parts as Pattern No. B615, but with the addition of a Wall Rosette and Cord.

These Sub-Station Instruments are suitable for use with any ordinary pattern Battery Intercommunication Telephone as Central Station Instrument, but when so used the Sub-Stations cannot be switched through to one another.
 

Last revised: July 07, 2020